Oh hai, I think I know you from a previous question :)
Hon, I would ask you to look deep within yourself. Are you a strong, maternal Cancer? If so, Pisces might be a better choice for you.
However if you don't consider yourself emotionally strong, and feel as though you require someone to impart THEIR strength to you, then I would recommend Scorpio. Scorpio is more of a caretaker type of personality, while Pisces likes to be taken care of.
Pisces will typically be sort of like an eternal little boy: lots of fun, but he might forget to pay the bills on time.
Scorpio is more brooding, and will be more dominant, but he'll always step up to the plate as far as seeing to his family.
I know you're conflicted. But you're very lucky to be making a choice between two wonderful men!
BTW, is it possible for you to share your ascending and moon signs?
Oh, and I'm a Pisces who has had serious relationships with all three Water signs, though I ended up marrying an Earth sign!